Precision Made. Disaster Ready. When the World Melts Down, Your Keys Won’t. Stainless Steel Full Stainless Steel construction: milled from solid 303 Stainless bar stock. Insanely Tough Designed and Engineered for ultimate toughness – tested to beyond 2,200 F. BIP-39 & more Designed for storing BIP-39 compliant 24-word seed phrases; will accept shorter phrases as well. Rotate Keys Rotate your keys at will, any time, for any reason – or no reason.